Physicians have long been puzzled by a condition called intracranial arterial dolichoectasia. There is recent evidence that people with dolichoectasia are more likely to have aortic aneurysms.

According to the researchers, physicians who encounter patients with small vessel disease should look for evidence of dolichoectasia. "If dolichoectasia is present, you should look for an associated abdominal aortic aneurysm and carefully search for associated cardiac symptoms," said Pierre Amarenco, M.D., of Bichat University Hospital in Paris.

Beyond the immediate clinical implications, the study may offer more important clues for further research. It may be that dolichoectasia causes or contributes to small vessel disease, or that the two have common causes.

Using MRI, Amarenco and his colleagues studied 510 patients who had suffered strokes and found that the subset of patients with dolichoectasia were more likely to have evidence of small vessel disease. There was a direct relationship between the diameter of the basilar artery, the cranial artery most often affected in dolichoectasia, and the severity of small vessel disease.

"This study is the first to show an association between intracranial arterial dolichoectasia and the whole spectrum of small vessel disease abnormalities, thus defining a new cerebrovascular syndrome," said Amarenco.

The researchers will continue to follow the patients in this study to try to determine which vascular or genetic factors contribute to the syndrome. They will also attempt to replicate their MRI data in an autopsy study of patients who died with dolichoectasia.